When you hang out with quilters long enough, the topic of bleeding will eventually come up. I've seen a lot of beautiful quilts, usually a red/light combo, ruined by bleeding. And of course, you don't know which fabric will bleed until it's sewn into the quilt! I personally have never had a quilt bleed, but I did have a quilt crock and it about broke my heart! Although it's hard to see below, you can see along the seam line in the center of the picture where it looks dirty. That's where the red fabric rubbed off onto the white fabric when it was folded and stored. I now fold it with a white sheet to avoid further damage. (To see the whole quilt, look for it on The Wednesday Quilt Show from Jan. 12. It's the 911 Tribute quilt.)
After this experience, I learned about Retayne (I have no affiliation with this company other than I like and use this product.) Retayne is used in fabric dyeing, but it also can be used to stop fabric from bleeding. I now wash every piece of fabric that comes in my house with Retayne before I use it. This is how I do it:
Retayne is a clear liquid that when used in the wash actually sets the dye and prevents it from bleeding in the future. Ask for it at your quilt shop. Don't bother with the little bottle, request the 16 oz. size. Follow the directions on the label. I have a front-loading machine, so I had to improvise. I use the shortest cycle (about 30 minutes) and the hot/cold setting with low spin and light soil levels. So far, it has worked for me, even though it is different from the label directions.
Synthropal, shown in the middle, is both a detergent and it prevents the excess dye from resetting on the fabric or other fabrics. Use Retayne on fabric before you sew it into the quilt and use Synthropal on a finished quilt that has already bled. What's the Dawn Ultra dish soap? I use it instead of Syntrhopal. It acts the same as Synthropal, believe it or not, and I've never had it fail me! Plus it's a lot cheaper and readily available everywhere. Make sure it says Dawn Ultra and don't use more than a tablespoon or two so you don't have suds all over everywhere!
Sort your fabrics before washing with Retayne. When the cycle is done, dry as normal. I find it's best not to use fabric softener or softener sheets. I never know if I'll need that fabric for applique or piecing, and with my method of freezer paper applique, the softener inhibits the glue from doing it's job properly. Sometimes I press the fabric at this point, but most often, I just fold it and add it to my stash. I'll press when I'm ready to use it, so why press twice, right?
I can't guarantee that you'll never have a fabric bleed after using these products, but I can tell you that I've never had a problem since I started using them. (BTW, you can wash your super-dark denim jeans and blacks in Retayne, too, to keep them from fading!)